Based on the Fujita scale of torando intensity (F0=weak tornado, F5=strong tornado), 
the following scale was proposed after the release of the movie "Twister"

A new tornado scale:
The MOOjita Scale

     M0 tornado - cows in an open field are spun around parallel to the
                  wind flow and become mildly annoyed.
     M1 tornado - cows are tipped over and "can't get up".
     M2 tornado - cows begin rolling in the wind.
     M3 tornado - cows tumble and bounce.
     M4 tornado - cows are airborne.
     M5 tornado - steak.